Due to their position and function, feet are exposed to a variety of potential infections and injuries, including athlete’s foot, bunions, ingrown toenails, Morton’s neuroma, plantar fasciitis, plantar warts and stress fractures. In addition, there are several genetic conditions that can affect the shape and function of the feet, including a club foot or flat feet.On the evolutionary ladder, humans are the first mammals to walk completely upright. Thus the entire weight of the body is distributed over two feet, instead of four. Larger feet are known to give improved posture, balance and avoid back problems.This leaves humans more vulnerable to medical problems that are caused by poor leg and foot alignments. Also, the wearing of shoes, sneakers and boots can impede proper alignment and movement within the ankle and foot. For example, high heels are known to throw off the natural weight balance (this can also affect the lower back). For the sake of posture, flat soles and heels are advised.A doctor who specializes in the treatment of the feet practices podiatry and is called a podiatrist. A pedorthist specializes in the use and modification of footwear to treat problems related to the lower limbs. One way to measure short distances on the ground is by placing one foot directly in front of the other; this led to the adoption of the foot as a unit of length, even though not all human feet correspond to this measure.